Backscatter communication method, excitation device, backscatter device, and receiving device

Abstract

Embodiments of this application disclose a backscatter communication method and a related apparatus. The method includes: An excitation device determines a first sequence, generates a first signal, and sends the first signal, where the first signal carries the first sequence; after receiving the first signal, a backscatter device modulates backscatter device data onto the received first signal to obtain a second signal, and backscatters the second signal, to implement first scrambling on the backscatter device data by using the first sequence; and a receiving device determines the first sequence, receives the second signal from the backscatter device, and demodulates the received second signal based on the first sequence, to obtain the backscatter device data carried on the second signal.

What is claimed is: 
     
       1. A method, comprising:
 determining, by an excitation device, a first sequence; 
 generating, by the excitation device, a first signal; 
 sending, by the excitation device, the first signal to a backscatter device; and 
 sending, by the excitation device, the first signal to a receiving device, wherein the receiving device receives backscatter device data from the backscatter device in a second signal different and separate from the first signal, wherein the first signal carries the first sequence, and wherein the first sequence is used by the backscatter device to perform first scrambling on the backscatter device data, the backscatter device data produced by the backscatter device. 
 
     
     
       2. The method according to  claim 1 , further comprising:
 determining, by the excitation device, a parameter of the first sequence, and using the parameter of the first sequence to determine the first sequence. 
 
     
     
       3. The method according to  claim 2 , further comprising:
 sending, by the excitation device, first indication information to the receiving device that receives the backscatter device data from the backscatter device, wherein the first indication information indicates the parameter of the first sequence. 
 
     
     
       4. The method according to  claim 3 , wherein the parameter of the first sequence is determined based on at least one of:
 a physical layer identifier of backscatter communication, a physical layer identifier of the excitation device, a physical layer identifier of the receiving device, time domain information of the first signal, or a frequency of the first signal. 
 
     
     
       5. The method according to  claim 2 , wherein the parameter of the first sequence comprises at least one of: a sequence type of the first sequence, an initial value of the first sequence, or a sequence shift value of the first sequence. 
     
     
       6. The method according to  claim 1 , further comprising:
 determining, by the excitation device, a parameter of the first signal. 
 
     
     
       7. The method according to  claim 6 , wherein the parameter of the first signal comprises at least one of:
 a subcarrier location of the first signal, a subcarrier spacing of the first signal, a time length of the first signal, a frequency hopping pattern of the first signal, or a transmit power of the first signal. 
 
     
     
       8. The method according to  claim 1 , further comprising:
 sending, by the excitation device, second indication information to the backscatter device and the receiving device, wherein the second indication information indicates a second parameter of a second sequence, and the second sequence is used for performing second scrambling on the backscatter device data. 
 
     
     
       9. The method according to  claim 1 , further comprising:
 receiving, by the excitation device, second indication information from the receiving device, and sending the second indication information to the backscatter device, wherein the second indication information indicates a second parameter of a second sequence, and the second sequence is used to perform second scrambling on the backscatter device data. 
 
     
     
       10. The method according to  claim 9 , wherein the second parameter of the second sequence comprises at least one of:
 a sequence type of the second sequence, an initial value of the second sequence, or a sequence shift value of the second sequence. 
 
     
     
       11. The method of  claim 1 ,
 wherein the first signal is used by the backscatter device to modulate the backscatter device data to obtain the second signal, and wherein the second signal is demodulated by the receiving device based on the first sequence to obtain the backscatter device data, and 
 wherein the first signal is received by the receiving device in a first path, wherein the second signal is received by the receiving device in a second path different from the first path, wherein the first path excludes the backscatter device, and wherein the first signal excludes the backscatter device data. 
 
     
     
       12. A method, comprising:
 receiving, by a backscatter device, a first signal from an excitation device, wherein the first signal is further received by a receiving device, the first signal carries a first sequence, and the first sequence is used to perform first scrambling on backscatter device data, the backscatter device data produced by the backscatter device; 
 modulating, by the backscatter device, the backscatter device data to the first signal to obtain a second signal, wherein the second signal carries the backscatter device data obtained after the first scrambling, the modulating comprising:
 performing, by the backscatter device, the first scrambling on the backscatter device data using the first sequence; and 
 
 backscattering, by the backscatter device, the second signal to the receiving device, the second signal being different and separate from the first signal. 
 
     
     
       13. The method according to  claim 12 , further comprising:
 determining, by the backscatter device, a second sequence; 
 performing, by the backscatter device, second scrambling on the backscatter device data using the second sequence; and 
 wherein the modulating, by the backscatter device, the backscatter device data onto the first signal to obtain the second signal comprises:
 modulating, by the backscatter device, the backscatter device data obtained after the second scrambling to the first signal to obtain the second signal. 
 
 
     
     
       14. The method according to  claim 13 , further comprising:
 receiving, by the backscatter device, second indication information from the excitation device or the receiving device, wherein the second indication information indicates a second parameter of the second sequence. 
 
     
     
       15. The method according to  claim 14 , wherein the second parameter of the second sequence comprises at least one of:
 a sequence type of the second sequence, an initial value of the second sequence, or a sequence shift value of the second sequence. 
 
     
     
       16. A method, comprising:
 receiving, by a receiving device, a first signal carrying a first sequence, wherein the first signal is further received by a backscatter device, and the first sequence is used by the backscatter device to perform first scrambling on backscatter device data, the backscatter device data produced by the backscatter device; 
 receiving, by the receiving device, a second signal from the backscatter device, wherein the second signal carries the backscatter device data obtained after the first scrambling, and wherein the second signal is different and separate from the first signal; and 
 demodulating, by the receiving device, the second signal based on the first sequence, to obtain the backscatter device data. 
 
     
     
       17. The method according to  claim 16 , further comprising:
 determining, by the receiving device, a parameter of the first sequence, wherein the parameter of the first sequence is used to determine the first sequence. 
 
     
     
       18. The method according to  claim 17 , further comprising:
 sending, by the receiving device, first indication information to an excitation device, wherein the first indication information indicates the parameter of the first sequence. 
 
     
     
       19. The method according to  claim 18 , further comprising:
 receiving, by the receiving device, second indication information from the excitation device, wherein the second indication information indicates a second parameter of a second sequence; 
 determining, by the receiving device, the second sequence based on the second parameter of the second sequence; and 
 descrambling, by the receiving device, a demodulated second signal based on the second sequence, to obtain the backscatter device data. 
 
     
     
       20. The method according to  claim 16 , further comprising:
 sending, by the receiving device, second indication information to an excitation device, wherein the second indication information indicates a second parameter of a second sequence. 
 
     
     
       21. The method according to  claim 16 , further comprising:
 sending, by the receiving device, third indication information to an excitation device, wherein the third indication information indicates a parameter of the first signal.